Ever since their inception, there has been an on-going drive to make computers, and their components, faster and smaller. In recent computing history, this evolution has included a migration from stand-alone network servers to rack network servers. Rack servers allow for several independent or interdependent servers to be housed within a single frame as a vertical stack. The frame, or rack, typically includes some common functions for all of the servers within the frame. Accordingly, the rack arrangement creates both space and cost savings.
The next generation of high density computing introduced blade servers. In the blade server design, a chassis about the size of a single rack server holds a number of blade servers that are slidably inserted into the chassis. Each blade server is a card that carries basic server components such as central processing unit and memory. The chassis includes components common to all servers, such as power, cooling units, input/output circuitry, so that each blade server need not carry these bulkier components. With blade servers, a single blade chassis can carry as much computing power as would have been taken up by a six foot high set of rack servers.
Moreover, blade servers and the blade chassis are arranged to permit hot swapping (i.e., insertion and removal) of the blade servers into and from the blade chassis, thereby enhancing the flexibility and portability of computing with blade servers. However, this hot-swapping capability in conventional blade servers requires specialized operating system drivers, hot-swap controllers, and/or other circuitry and drivers for carrying the hot-swapping capability. Moreover, these components occupy space on the board, which is always at a premium, and complicate the compatibility of each blade server with the blade chassis. These issues frustrate the instant use that blade servers were intended to provide.
For these and other reasons, conventional blade servers and their chassis still face challenges in implementing a hot-swapping capability.